The Relationships between Oxygen Consumption and Duration of Pupal-Adult Development in the Silkworm Bombyx mandarina.

  • SHEN Weide
    Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology
  • HAMANO Kunikatsu
    Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology

Search this article

Description

Duration of pupal stage of Bombyx mandarina is 2 to 4 times longer than that of Bombyx mori. We attempted to investigate whether this represents a state of diapause or not. Based on the pupal duration and oxygen consumption, developmental pattern of pupae in B. mandarina was mainly classified to three types, A, B and C, though these were dependent on the rearing seasons. In the spring season, typical type-A pupae had the shortest duration the same as in B. mori. Type-B pupae were intermediate of type-A and C. Pupae that had the longest duration were classified as type-C. Oxygen consumption decreased quickly soon after pupation and each type showed a typical U-shape respiration curve during pupal stage. Oxygen consumption in type-C animals was lowest of all 3 types. It reached extremely low levels of 5μl/hr/g, which went on for more than 2 weeks. When the type-A pupae were maintained in low temperature, pupal duration was elongated in proportion to the temperature decrease. However, in this experiment the respiratory activity curve in the lowest temperature of 20°C was clearly different from that of type-C pupae. In another experiment, type-A and B pupae showed increased respiration, proportionally to the temperature increase, while there was no increase in respiration of the C-type animals when subjected to the different temperatures. Finally, we can conclude that the low level of oxygen consumption in the C-type animals is characteristic to diapausing insects and this is in good accordance with the insensitivity of these animals to different temperatures. It was consequently determined that in B. mandarina there is a kind of facultative diapause in pupal stage.

Journal

Citations (1)*help

See more

Details 詳細情報について

Report a problem

Back to top